Hey, it's been mentioned as a non-issue. I'm going to paste a quote from a QTUM team member, but take it with a grain of salt, as I am copying and pasting it from the Slack channel/discussion.

qtum-earlz [6:06 AM]
We are aware that several people have scanned Qtum Core and found that some anti-virus companies report that it contains a virus or trojan. These are false positives, we have made sure that our binaries were not tampered with on Github, and additionally we use Gitian so that any community member can confirm that we are not tampering with the compiled release files. If you would like to compare your Windows 64bit files to our own, these are the sha256sum hashes:

If you are interested in comparing the files/hashes yourself, I could post the second part of qtum-earlz's quote so that you can ensure for yourself that the file is safe.